89 research outputs found
Zinc(II) complexes of indole thiosemicarbazones: DNA/protein binding, molecular docking and in vitro cytotoxicity studies
No full textFour Zn(II) complexes (1–4) featuring indole thiosemicarbazones were synthesized and well-characterized by elemental analyses and various spectroscopic (UV–Vis, FT-IR, 1H NMR, 13C NMR and mass) techniques. The single crystal X-ray crystallographic study revealed a tetrahedral geometry for complexes 1 and 3. The interactions of the Zn(II) complexes 1–4 with calf thymus DNA (CT DNA) were examined by UV–Vis spectroscopy and viscosity measurements, which implied that the complexes bound to CT DNA via intercalation, and complex 4 showed a higher binding affinity than the other complexes. The protein binding interaction of the complexes was monitored by fluorescence and absorption techniques, which showed that the complexes could bind effectively with bovine serum albumin (BSA) and the type of quenching mechanism was found to be static. Synchronous fluorescence experiments showed the changes in the conformations of the protein micro regions. Molecular docking studies were performed in order to get a better picture of the binding of the complexes with the molecular targets DNA hexamer and BSA. The in vitro cytotoxicity of the complexes against two human cancer (A549 and MCF7) cell lines, two human non-tumorigenic (MCF-10A and HEK-293) cell lines and one non-cancerous mouse fibroblasts (L929) cell line was evaluated using an MTT assay. Complex 4, which has an N-terminal cyclohexyl group, showed moderate activity [IC50 = 37.9 (A549) and 60.3 μM (MCF7)] that was comparable with the familiar anticancer drug cisplatin. Also, fortunately, the activity of complex 4 was found to be specific to cancer cells. The apoptosis cell death mechanism for complex 4 was assessed by the Hoechst staining method.No Full Tex
Polymerization of aniline in layered · (M=Nb,Ta)
No full textLayered Bronsted acids, · (M=Nb, Ta) possessing a rutile-related structure, readily intercalates aniline giving . Oxidation of the latter in air at 130°C polymerizes the interlayer aniline to give nanocomposites (PANI=polyaniline). Characterization of the composites by various physical methods reveals that the polymerization is near-quantitative, occurring within the galleries of the inorganic host. EPR spectroscopy shows a single resonance at g=2.003 which is characteristic of PANI, indicating that the inorganic host does not participate in the oxidative polymerization of aniline
Soft chemical synthesis of new layered and three-dimensional oxide hydrates, hxVxW1-xO3×yH2O, related to WO3×2 H2O and WO3. times.1/3 H2O
No full textTwo new vanadium-tungsten oxide hydrates of the formulas, H0.125V0.125W0.875O3.1.5H2O (I) and Ho.33V0.33W0.67O3.1/3H2O (II), have been synthesized by acid-leaching of LiVWO6 with aqueous HNO3/HCl. While phase I obtained by treatment of LiVWO6 with dilute HNO3/HCl possesses an orthorhombic structure (a = 7.77(3), b = 13.87(6), c = 7.44(3) angstrom) related to WO3.2H2O, phase II, prepared by refluxing LiVWO6 with concentrated HNO3, is isostructural with WO3.1/3H2O. Dehydration of II around 330-degrees-C yields a hexagonal phase (III, a = 7.25(4), c = 7.74(3) angstrom) isotypic with hexagonal WO3. Both land III exhibit redox and acid-base intercalation reactivity characteristic of layered and tunnel structures
Towards rational synthesis of inorganic solids
No full textThere have been major advances in the past couple of years in the rational synthesis of inorganic solids: synthesis of mercury-based superconducting cuprates showing transition temperatures up to 150 K; ZrP2-xVxO7 solid solutions showing zero or negative thermal expansion; copper oxides possessing ladder structures such as La1-xSrxCuO2.5; synthesis of mesoporous oxide materials having adjustable pore size in the range 15-100 Angstrom; and synthesis of a molecular ferromagnet showing a critical temperature of 18.6 K. Despite great advances in probing the structures of solids and measurement of their physical properties, the design and synthesis of inorganic solids possessing desired structures and properties remain a challenge today. With the availability of a variety of mild chemistry-based approaches, kinetic control of synthetic pathways is becoming increasingly possible, which, it is hoped, will eventually make rational design of inorganic solids a reality
Rapport evaluatie nautisch onderzoek havenmond van Hoek van Holland
No full textTen behoeve van de bouw van de nieuwe havenmond nabij Hoek van Holland, de definitieve toegang naar Europoort en de aanleg van de naderingsgeul voor diepstekende schepen, is in de periode van 1960 tot heden veel onderzoek verricht. Als onderdeel van de afsluiting van de werkzaamheden wordt een samenvattende rapportage én evaluatie gemaakt van alle "hiertoe verrichte nautische onderzoekingen. Het onderhavige rapport behandelt daartoe dat gedeelte van de uitgevoerde onderzoeken, dat verricht werd door/bij het Nederlands Scheepsbouwkundig Proefstation te Wageningen. Het onderzoek dat door het N.S.P. in de verschillende fasen van de realisatie van de nieuwe havenmonden werd uitgevoerd kan naar de aard van de toegepaste methodieken in twee groepen worden onderverdeeld. Eén groep bevat het onderzoek waarbij gekozen is voor metingen aan schaalmodellen van schepen in een fysisch model van de vaarsituatie. Een tweede groep omvat onderzoeken welke meer gericht zijn op de bestudering van het integrale gedrag van het "mens-schip-omgevings syteem", waarbij inschakeling van een scheepsmanoeuvreersimulator werd geprefereerd
Double nuclear spin switching in single quantum dots
No full textHyperfine interaction in a quantum dot produces a spin-coupled system between an injected electron and a few tens of thousands of nuclei in the electron wavefunction. We report here that the double bistable phenomenon of nuclear spin polarization (NSP) can be observed by sweeping three control parameters. All the observations indicate that the NSP has three stable branches under a longitudinal magnetic field, whereas the number of the stable branches of NSP has been believed to be two at most. The incorporation of the electron spin relaxation due to the nuclear spin fluctuation enables reproduction of the observed features of the NSP and the electron spin polarization
Vergelijkbaarheid van diverse golfverwerkingsprogramma's
No full textVergelijking van de golfverwerkingsprogramma's van het Waterloopkundig Laboratorium (WL), KNMI, de Deltadienst (Rijkswaterstaat) en het Nederlands Scheepsbouwkundig Proefstation (NSP)
Non-linear optical response of rutile-related oxides, LiM(V)M(VI)O(6), and their derivatives obtained by ion-exchange and intercalation
No full textPolycrystalline samples of oxides of the general formula LiM(V)M(VI)O(6) (M(V) = Nb, Ta; M(VI) = Mo, W), crystallizing in a non-centrosymmetric (space group P (4) over bar 2(1)m) trirutile structure, exhibit second harmonic generation (SHG) of 1064 nm radiation with efficiencies 15-45 times that of alpha-quartz; interestingly, the SHG response is retained by the protonated derivatives HM(V)M(VI)O(6) . xH(2)O, and their n-alkylamine intercalates as well
A new charge density wave oxide, and its tungsten analogue obtained by topotactic reduction of (M=Mo,W) brannerites
No full textWe report the synthesis of two new low-dimensional oxides, LiVMO(5) (M = Mo, W), which contain S = 1/2 transition-metal atoms, V-IV:3d(1) and Mo-V:4d(1)/W-V:5d(1), by topotactic reduction of the LiVMO(6) brannerites in hydrogen. LiVMO(5) crystallizes in orthorhombic structures related to the parent brannerite structure. The VMO(5) network of the new oxides is likely to correspond to one of the A(2)X(5) structures predicted by A. F. Wells (Philos. Trans. R. Soc. London A, 1984, 312, 589). LiVMoO5 is metallic showing a charge density wave (CDW) instability around 230 K; interestingly, LiVWO5 is a paramagnetic semiconductor down to 20 K
Copper complexes as prospective anticancer agents: <i>in vitro</i> and <i>in vivo</i> evaluation, selective targeting of cancer cells by DNA damage and S phase arrest
No full textThe thiosemicarbazone-based copper(i) complexes causing S phase arrest and apoptosis involving the mitochondrial controlled pathway has been investigated.</p
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